Fermented beverages, such as beer and wine, are complex solutions comprising various organic compounds such as haze-forming components that, upon aging and chilling to about 0° C., undergo undesirable reactions and destabilize the beverage to cause observable cloudiness (“chill haze”) and reduced physical shelf life. Common chill haze-forming components are certain proteins and polyphenols derived from ingredients during the fermentation process such as malt or hops. Proteins, particularly those rich in proline and glutamic acid, can interact with polyphenols, particularly tannins, creating a cloudy product at low temperatures, close to 0° C.
Removal of haze-forming components has been accomplished by employing silica which selectively adsorbs and/or flocculates these components. For example, U.S. Pat. No. 4,027,046 describes a colloidal silica sol for reduction of haze having a surface area of from 50 to 600 m2/g. Another form of silica, known as silica microgels, has been proposed to remove haze-forming proteins from a liquid as disclosed in U.S. Pat. No. 7,048,859 but the silica microgels must be used in conjunction with an organic polymer which acts as a flocculating agent.
Despite the advances of using various forms of silica for removal of haze-forming components, there is still a need for a more efficient silica to reduce chill haze without the requirement of using an organic polymer which acts as a flocculating agent. This would be particularly desirable to avoid any undesirable interaction between treated fermentation liquid products and said organic polymer.